PROCESS FOR ASSEMBLING CAMERA MODULE
A process for assembling a camera module is provided. Firstly, a first conductive bump and a second conductive bump are placed on a signal terminal of a substrate and a contact pad of an image sensing chip, respectively. Then, the substrate and the image sensing chip are laminated, so that the first conductive bump and the second conductive bump are combined together and the signal terminal of the substrate and the contact pad of the image sensing chip are electrically connected with each other. Then, an underfill is applied to a region between the substrate and the image sensing chip. Since the two conductive bumps are connected with each other by the assembling process, the quality of the camera module of the present invention is enhanced.
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The present invention relates to a process for assembling a camera module, and more particularly to a process for assembling a camera module of a portable electronic device such as a mobile phone or a personal digital assistant.
BACKGROUND OF THE INVENTIONConventionally, a camera module is assembled by a flip-chip packaging technology.
The functions of respective components of the camera module 1 will be illustrated with reference to
After the conventional camera module 1 is produced by the above assembling process, a reliability test is performed to test the reliability of the conventional camera module 1. Generally, the items of the reliability test comprises a heat flow testing item, a high temperature testing item, a high humidity testing item, a high and low temperature impact testing item, a flexibility testing item, an UV exposure testing item, an anti-drop impact testing item, an automatic focus durability testing item, and the like. The reliability test found that the conventional camera module 1 may fail to pass the high and low temperature impact testing item and the anti-drop impact testing item. In other words, the capability of the conventional camera module 1 to withstand impact is usually insufficient. Therefore, there is a need of providing a camera module having strong structural strength in order to enhance the quality of the camera module.
SUMMARY OF THE INVENTIONAn object of the present invention provides a process for assembling a camera module in order to enhance the reliability of the camera module.
In accordance with an aspect of the present invention, there is provided a process for assembling a camera module. Firstly, a first conductive bump and a second conductive bump are placed on a substrate and an image sensing chip, respectively. The first conductive bump is arranged on a signal terminal of the substrate. The second conductive bump is arranged on a contact pad of the image sensing chip. Then, the substrate and the image sensing chip are laminated, so that the first conductive bump and the second conductive bump are combined together and the signal terminal and the contact pad are electrically connected with each other. Then, an underfill is applied to a region between the substrate and the image sensing chip.
In an embodiment, the process includes a step of fixing a camera lens assembly onto the substrate. The camera lens assembly includes a lens mount and a lens. The lens is aligned with an image sensing zone of the image sensing chip.
In an embodiment, the first conductive bump and the second conductive bump are conductive core bumps. The volume of the first conductive bump is larger than that of the second conductive bump. When the first conductive bump and the second conductive bump are combined together, the second conductive bump is covered by the first conductive bump, so that electrical connection between the first conductive bump and the second conductive bump is established.
In an embodiment, the substrate is a rigid-flex printed circuit board, a copper-clad laminate substrate (FR4 substrate) or a ceramic substrate.
In an embodiment, the rigid-flex printed circuit board includes a first rigid printed circuit board, a second rigid printed circuit board and a flexible printed circuit board. The flexible printed circuit board is sandwiched between the first rigid printed circuit board and the second rigid printed circuit board. The signal terminal is formed on the first rigid printed circuit board.
In an embodiment, the first conductive bump is a conductive core bump, and the second conductive bump is a conductive cavity bump. When the first conductive bump and the second conductive bump are combined together, the first conductive bump is accommodated within a cavity part of the second conductive bump to electrically connect with each other.
In an embodiment, the process further includes steps of producing a prototypal conductive block by using a ball mounting head, controlling the ball mounting head to press against the prototypal conductive block, and pulling back the ball mounting head, thereby forming the conductive cavity bump.
In an embodiment, the first conductive bump is a conductive cavity bump, and the second conductive bump is a conductive core bump. When the first conductive bump and the second conductive bump are combined together, the second conductive bump is accommodated within a cavity part of the first conductive bump to electrically connect with each other.
In an embodiment, the process further includes steps of producing a prototypal conductive block by using a ball mounting head, controlling the ball mounting head to press against the prototypal conductive block, and pulling back the ball mounting head, thereby forming the conductive cavity bump.
In an embodiment, the first conductive bump and the second conductive bump are made of gold.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
As previously described, the conventional camera module has poor impact resistance. In order to obviate the drawbacks encountered from the prior art, the present invention provides a process for assembling a camera module by aiming at the connection between the signal terminal and the contact pad.
Please refer to
Please refer to
The process for assembling the camera module according to the first embodiment of the present invention has been described above. In accordance with a key feature of the present invention, the conductive bumps 23 and 24 are respectively placed on the substrate 21 and the image sensing chip 22. By laminating the substrate 21 and the image sensing chip 22, the conductive bumps 23 and 24 of these two components are jointed together, so that the substrate 21 and the image sensing chip 22 are combined together. Since the first conductive bump 23 is placed on the signal terminal 2111 of the substrate 21, after the substrate 21 and the image sensing chip 22 are laminated and combined together, the signal terminal 2111 and the contact pad 222 are electrically connected with each other through the first conductive bump 23 and the second conductive bump 24. In other words, the joint between the first conductive bump 23 and the second conductive bump 24 can enhance the connection between the signal terminal 2111 and the contact pad 222 and improve the connecting strength between the substrate 21 and the image sensing chip 22.
The present invention also provided a second embodiment.
As shown in
Please refer to
In this embodiment, before the step of placing the conductive cavity bump 34, the conductive cavity bump 34 is previously formed and then the further steps are done. A process for forming the conductive cavity bump 34 will be illustrated as follows.
The present invention also provides a third embodiment. In this embodiment, the first conductive bump is a conductive cavity bump, and the second conductive bump is a conductive core bump. The assembling process of the third embodiment is substantially identical to that of the second embodiment, except that the conductive core bump is placed on the image sensing chip and the conductive cavity bump is placed on the substrate. The further assembling steps are similar to those of the second embodiment, and are not redundantly described herein.
From the above description, since the first conductive bump and the second conductive bump are respectively placed on the signal terminal of the substrate and the contact pad of the image sensing chip, the adhesion between the substrate and the image sensing chip is enhanced when the substrate and the image sensing chip are laminated and combined together via two conductive bumps. Moreover, the reliability test demonstrated that, when compared with the conventional camera module, the camera module of the present invention has good results in the high and low temperature impact testing item and the anti-drop impact testing item.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Claims
1. A process for assembling a camera module, said process comprising steps of:
- placing a first conductive bump and a second conductive bump on a substrate and an image sensing chip, respectively, wherein said first conductive bump is arranged on a signal terminal of said substrate, and said second conductive bump is arranged on a contact pad of said image sensing chip;
- laminating said substrate and said image sensing chip, so that said first conductive bump and said second conductive bump are combined together and said signal terminal and said contact pad are electrically connected with each other; and
- applying an underfill to a region between said substrate and said image sensing chip.
2. The process for assembling a camera module according to claim 1 further comprising a step of fixing a camera lens assembly onto said substrate, wherein said camera lens assembly comprises a lens mount and a lens, and said lens is aligned with an image sensing zone of said image sensing chip.
3. The process for assembling a camera module according to claim 1 wherein said first conductive bump and said second conductive bump are conductive core bumps, and the volume of said first conductive bump is larger than that of said second conductive bump, wherein when said first conductive bump and said second conductive bump are combined together, said second conductive bump is covered by said first conductive bump, so that electrical connection between said first conductive bump and said second conductive bump is established.
4. The process for assembling a camera module according to claim 1 wherein said substrate is a rigid-flex printed circuit board, a copper-clad laminate substrate (FR4 substrate) or a ceramic substrate.
5. The process for assembling a camera module according to claim 4 wherein said rigid-flex printed circuit board comprises a first rigid printed circuit board 1, a second rigid printed circuit board and a flexible printed circuit board, said flexible printed circuit board is sandwiched between said first rigid printed circuit board and said second rigid printed circuit board, and said signal terminal is formed on said first rigid printed circuit board.
6. The process for assembling a camera module according to claim 1 wherein said first conductive bump is a conductive core bump, and said second conductive bump is a conductive cavity bump, wherein when said first conductive bump and said second conductive bump are combined together, said first conductive bump is accommodated within a cavity part of said second conductive bump, so that electrical connection between said first conductive bump and said second conductive bump is established.
7. The process for assembling a camera module according to claim 6 further comprising steps of producing a prototypal conductive block by using a ball mounting head, controlling said ball mounting head to press against said prototypal conductive block, and pulling back said ball mounting head, thereby forming said conductive cavity bump.
8. The process for assembling a camera module according to claim 1 wherein said first conductive bump is a conductive cavity bump, and said second conductive bump is a conductive core bump, wherein when said first conductive bump and said second conductive bump are combined together, said second conductive bump is accommodated within a cavity part of said first conductive bump, so that electrical connection between said first conductive bump and said second conductive bump is established.
9. The process for assembling a camera module according to claim 8 further comprising steps of producing a prototypal conductive block by using a ball mounting head, controlling said ball mounting head to press against said prototypal conductive block, and pulling back said ball mounting head, thereby forming said conductive cavity bump.
10. The process for assembling a camera module according to claim 1 wherein said first conductive bump and said second conductive bump are made of gold.
Type: Application
Filed: Aug 2, 2010
Publication Date: Sep 15, 2011
Applicant: PRIMAX ELECTRONICS LTD. (Taipei)
Inventors: Chien-Nan Yu (Taipei), Chung-Feng Tsao (Taipei), Ying-Chieh Chen (Taipei), Szu-Hao Lyu (Taipei), Ching-Lung Jao (Taipei), Hang-Kau Khor (Taipei)
Application Number: 12/848,700
International Classification: H01L 31/18 (20060101);